WIPP/SRL international in situ testing program: MIIT (Materials Interface Interactions Tests)

On July 22, 1986, the largest and most cooperative international effort directed at in situ testing of simulated waste glasses was officially begun. This program, called the Materials Interface Interactions Tests (MIIT), involves the underground emplacement of almost 2000 simulated HLW samples, package components, and eologic samples in the bedded salt site at the Waste Isolation Plant (WIPP), near Carlsbad, New Mexico. Samples were supplied by researchers in the United States, France, Germany, Canada, Belgium, Japan, and the United Kingdom. Data and sample performance are being assessed and analyzed by laboratories and universities in each of the participating countries and additional nations also. Samples have been retrieved after 0.5, 1, and 2 years of burial with only the 5 year samples still in test. There are hundreds of samples available for study and many analyses are currently in progress. At present, even though only a small portion of all the data available has been obtained and analyzed, important effects and trends are already emerging. An overview of the MIIT will be presented along with a summary of preliminary findings on performance of Savannah River (SR) waste glass in the WIPP MIIT. 20 refs., 8 figs.